1. Field of the Invention
The subject invention relates to a system and method for high-speed massive magnetic imaging on a spin-stand. In particular, the present invention directs itself to a magnetic hard disk rotatably mounted on a spin-stand system with a magnetic read head being further mounted on the spin-stand system to read data from the magnetic hard disk. Particularly, this invention directs itself to an orthogonal scanning of the magnetic hard disk to obtain a two-dimensional image of the magnetic data. More particularly, this invention directs itself to a method of “track-centering” and “track-following” to account for eccentricity of the hard disk with respect to the center of rotation of the spin-stand spindle to which the magnetic hard disk is mounted. Moreover, this invention directs itself to a technique of whole-track imaging of magnetic hard disks that are off-centered with respect to the center of rotation of the spin-stand spindle. Further, this invention is directed to a processor means for receiving, interpreting, translating, and storing data measured by the magnetic read head.
Additionally, this invention is directed to a method for establishing alignment of the magnetically read data. More particularly, the method for establishing alignment of the magnetically read data is based upon an alignment algorithm controlled by the processor means.
2. Prior Art
The imaging of magnetization patterns recorded on hard disk drives is a valuable tool which can appreciably aid future progress in the design of recording systems. Magnetic imaging is commonly performed using magnetic force microscopy (MFM). However, magnetic force microscopy has intrinsic limitations such as a low rate of image acquisition, a limited imaging area, special requirements for preparation of the sample to be imaged, and the virtual impracticality of numerous accumulations of images of the same target area to increase the signal-to-noise ratio.
Utilizing the system and method for high-speed massive magnetic imaging, raw image acquisition is performed by scanning a selected (target) area of a hard drive disk by a conventional magneto-resistive (MR) read head. This scanning is performed in two orthogonal (along-track and cross-track) directions. Scanning in the along-track direction is realized due to the rotation of the disk, while scanning in the cross-track direction is performed by using small and accurately controlled radial displacements of the head. This method for scanning has the following advantages over conventional MFM imaging: the image acquisition is performed under similar conditions as in commercial hard disk drives; there is a high rate of image acquisition; there is a vast imaging area; and numerous images of the same target area can be quickly accumulated in order to increase the signal-to-noise ratio.